Aerodynamic Coefficients of a Cube in Hypersonic Flow for All Attitudes

During reentry, spacecraft components are often modeled by simple geometries such as cubes, prisms, and cylinders, and their aerodynamics have been shown to vary with angle of attack. This work investigates the aerodynamics of a cube in Mach 6 flow for all flight attitudes as an example of a generic space debris geometry. Forces and moments acting on the cube are calculated using computational fluid dynamics at 16 orientations, which are chosen to exploit symmetry. The data is then extended to 218 independent orientations, covering all possible incident flow angles. Correlations from spherical harmonic basis functions, selected using sparse regression, are then developed for the force and moment coefficients. Regression errors are small relative to previous studies, demonstrating that spherical harmonics model the coefficients efficiently. We calculate maximum regression errors of up to 1% and 12% of the maximum force and moment coefficient, respectively, compared to 15% and 27% of the maximum force and moment coefficient presented in prior work. The correlations compared well to results from Mach 6 free-flight experiments conducted in the The University of Southern Queensland’s hypersonic wind tunnel, TUSQ. The correlations also compared well to published results from Mach 7 free-flight experiments conducted in the German Aerospace Center’s (DLR) Hypersonic Wind Tunnel, H2K.